In the prior art one widely used method of constructing a rocket combustion chamber involves forming an inner wall, machining longitudinal channels into the wall and then forming an outer wall by techniques such as electroforming or the like. With this method, the minimum dimensions of the cooling channels is restructed due to machining limitations and other factors such as the type of material being used. Additional difficulties are presented if it is desired to have the cooling channels arranged in a spiral configuration around the rocket chamber.
Photoetching techniques have been used in the past to form in metal rings radial slots on the order of 0.005 to 0.125 inches in depth and extending radially inwardly between large cooling channels formed by stacking the metal rings and the interior of the chamber formed thereby. None of these slots align with ones in adjacent rings so that the interior of the rocket chamber is a porous like surface through which coolant is injected to provide transpirational cooling.
In rocket chambers of the prior art, fuel is often directed through the cooling passages in the wall of the rocket chamber. The fuel is usually delivered to a manifold around the rocket chamber by means of pipes or conduits connected between the manifold and a fuel tank in which the fuel is stored. Such pipes or conduits add weight to the engine, as well as causing problems of assembling and presenting dangers of external leakage.